Workplace Safety and Insurance
Appeals Tribunal

Established in 1985, the Workplace Safety and Insurance Appeals Tribunal (WSIAT) is the final level of appeal to which workers and employers may bring disputes concerning
workplace safety and insurance matters in Ontario. WSIAT has always been separate from and independent of the
Workplace Safety and Insurance Board.

Highlights of Noteworthy Decisions

Decision 2574 11

2/12/2014

M. Crystal - A. Lust - D. Broadbent

Cancer (colon)

Evidence (epidemiological)

Firefighter

Medical report (opinion of medical assessor)

The worker was a firefighter. He was diagnosed with colon cancer in 2008 and died 2010. In Decision No. 2574/11I2, the Panel found that the presumption in s. 15.1(4) did not apply, pursuant to s. 5(1) of O. Reg. 253/07, because the worker had reached age 61 before the diagnosis. The Panel then adjourned to obtain a report from a Tribunal medical assessor.The Panel was aware that epidemiological information had been prepared or collected to assist the Legislature in its deliberations concerning enactment of O. Reg. 253/07. The Panel provided this epidemiological information to the assessor.The assessor noted two important epidemiological shortcomings. First, there was virtually no personal exposure date for the firefighters under study. Secondly, data on firefighters' smoking histories was almost universally unavailable. The assessor found the link in the literature between workplace exposure associated with firefighters and development of colorectal cancer to be tenuous and concluded that it was medically possible that the cancer was related to work as a firefighter but not medically likely. The assessor also found the worker's smoking to be approximately as plausible as an explanation for the cancer. The Panel interpreted this to mean that neither the worker's smoking history nor his firefighting exposure was a medically likely explanation for this cancer.The estate submitted that the enactment of the presumption in O. Reg. 253/07 was evidence to support a probable causal linkage between colorectal cancer and firefighting exposure. However, the Panel noted that a statutory presumption is not evidence but, rather, a framework for considering evidence. The assessor considered the epidemiological evidence, noted its shortcomings and found that a causal relationship was not probable. In any event, the presumption was not applicable in this case.The Panel concluded that firefighting exposure was not a significant contributing factor to the worker's cancer. The employer's appeal was allowed.